1. Is a Shorter Bar an Effective Solution to Avoid Bar Dislocation in a Nuss Procedure? 
Marco Ghionzoli, MD, PhD, Gastone Ciuti, PhD, Leonardo Ricotti, PhD, Francesca Tocchioni, MD, Roberto Lo Piccolo, MD, Arianna Menciassi, PhD, Antonio Messineo, MD 
The Annals of Thoracic Surgery 
Volume 97, Issue 3, Pages (March 2014)
DOI: /j.athoracsur
Copyright © 2014 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Postoperative lateral chest roentgenograms in 3 different patients: (a) patient with a Nuss bar in place: the angle formed by the bar with horizontal line is less than 15 degrees. (b) Patient with a Nuss bar mildly dislocated (angle between 15 and 30 degrees). (c) Patient with a Nuss bar moderately dislocated (angle between 30 and 60 degrees) which required an early bar removal.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2014 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Fixed constraints (A) and (B) and force applied (C) on a computer-assisted design model of the bar, imported in the finite element model simulation environment.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2014 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Computer-assisted design representation of a Nuss bar (with stabilizers). Bar curvature is represented by the angle θ that bar extremities (or stabilizers) form with the central (flat) part of the bar. In the representation, F represents the force exerted by the sternum on the bar, which is placed non-symmetrically with respect to the bar center, thus generating a torque τ. Such torque induces bar rotation, which is normally prevented by sutures able to generate a reaction torque τR.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2014 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Results of the finite element model simulations performed on a (A) short bar and on a (B) long bar; stress values are graphically shown as a color map. A specific stress value corresponding to the stabilizer regions is evident in the high-magnification images for both bar types.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2014 The Society of Thoracic Surgeons Terms and Conditions

6. Fig 5
In this graph, stress values at the stabilizer area versus bar length are reported. This simulation was conducted on an average chest size configuration (D); 7 different bar lengths (♦) have been tested. Dashed line represents data trend.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2014 The Society of Thoracic Surgeons Terms and Conditions